WHAT IS CHEMOTHERAPY?

Chemotherapy is the use of drugs called cytotoxic (cell-killing) drugs that either kill cancer cells or prevent them from dividing. It is used in combination with surgery to destroy any cells that may have remained in the surgical area or spread to other parts of the body. Chemotherapy is an adjuvant therapy. In other words, it is used in addition to the primary therapy.

Sometimes chemotherapy is used before surgery to shrink the tumor, and improve the results of surgery. In this case it is called neoadjuvant therapy.


Addison R. Tolentino, MD – “I encourage my patients to set expectations.”

Chemotherapy is given intravenously or in pill form. In either case, the drugs spread throughout the body and attack cancer cells wherever they might be. For this, chemotherapy is called a systemic treatment, unlike radiation therapy and surgery, which are considered local treatments.

How Chemotherapy Works

The process of cell division follows specific steps. First, the genetic material (DNA) in the nucleus forms strands called chromosomes. Then the chromosomes divide into two sets, and the cell enlarges. Finally the cell splits into two identical cells, each with its own set of DNA.

Chemotherapy drugs interfere with various parts of this cycle, making it difficult for the cells to reproduce and repair themselves. Often several different drugs are used simultaneously in order to target different parts of the cycle and achieve the best result.

Addison R. Tolentino, MD – “Not every patient needs chemotherapy.”

How Chemotherapy is Given
Some chemotherapy drugs come in pill form, and you take them just as you would any other pill. Others are given by injection into a vein. These injections can be given in a private doctor’s office, in a hospital, or in a cancer center.

Intravenous chemotherapy is given in cycles. For example, a dose every two to four weeks. This allows the normal cells in your body to recover between treatments. The full course of therapy takes three to twelve months, but could be longer or shorter depending on your particular case.

If you are on intravenous chemotherapy, you will receive the injections in an oncologist’s office, or at an outpatient center. Before you receive the scheduled dose, the nurse will draw your blood, to check whether the treatment has affected the blood-producing cells in your bone marrow, or the function of your liver. If your results are too far below normal, your oncologist may decide to lower the dose, or postpone the treatment.

If your results are acceptable, the nurse will take you to the treatment area and start the IV (intravenous line) through which the drug will be injected. Then the drug will be administered. Some drugs are given as a rapid injection, others are dripped in slowly over a longer period—sometimes up to three hours. Generally you won’t feel any discomfort.

Personalized Medicine
Personalized treatment selection has been successful in breast and lung cancer. Today we have the tests necessary to develop molecular profiles that will make treatment of colorectal cancer both tumor-specific and patient-specific. These tests are important because they can predict which patients have increased risk of side effects, or increased probability of benefiting from the treatment. This allows the oncologist to create a tailored treatment program that will be personalized to your particular case.

Be sure to ask your medical team whether all necessary tests have been ordered to optimize your care.

Clinical Trials
Physicians are constantly searching for new drugs and combinations of drugs that may prove to be more effective than existing therapies. Check out the Clinical Trials section, then ask your physician how you may benefit from an ongoing trial in your area. The Colon Cancer Alliance offers a service where healthcare professionals will do the research and matching for you.

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